Spring cushioning device for clustered cylinder lifts

ABSTRACT

Spring cushioning devices are provided in each cylinder of a clustered cylinder lift, each device including a single coil-type compression spring operable to cushion its associated cylinder during both extension and retraction thereof.

[56] References Cited UNITED STATES PATENTS Frank Howard Field 133 East Virginia Blvd., Jamestown, N.Y. 14701 United States Patent [72] Inventor Primary Examiner-Martin P. Schwadron Assistant Examiner-Irwin C. Cohen Attorney-Bean & Bean ABSTRACT: Spring cushioning devices are provided in each cylinder of a clustered cylinder lift, each device including a single coil-type compression spring operable to cushion its associated cylinder during both extension and retraction thereof.

52 mm 21 91 b l 0 F CYLINDER LIFTS 6 Claims, 8 Drawing Figs. [52] Field of 45 X XXX co 555 wnmmm H 222 2 999 9 an .m

t. a H mm m: m m nea I .m owfl mmmmmd aua a AKTLMR 488534 561466 999999 111111 058616 1 420645 870002 227926 987773 ,32 1 23 233 .13 APP ll] 25 224 [[l [54] SPRING CUSHIONING DEVICE FOR CLUSTERED [51] Int.

PATENTEDUBT 19 I9?! 3.613.516

SHEET 1 BF 3 INVENTOR.

FQHNK HOW/92D F161. 0

ATTORNEYS PATENTEDucI 19 ISTI 3,613,516

SHEET 2 BF 3 INVENTOR. FRANK HOVWIRD F/'ZD A TTOP/VFYS SPRING CUSHIONING DEVICE FOR CLUSTERED CYLINDER LIFTS BACKGROUND OF THE INVENTION Elevator installations employing a pair of clustered cylinder lifts arranged laterally of an elevator car to be lifted thereby are presently in use. One difficulty experienced with this type of elevator lift is that the elevator car is subject to jolting when the cylinders forming the clusters are moved into both their fully extended and retracted positions.

SUMMARY OF THE INVENTION The present invention is directed to a novel spring cushioning device designed for elevator clustered cylinder lifts, which is adapted to prevent jolting and/or sharp accelerations of an elevator car.

The spring cushioning device of the present invention is particularly adapted for use with hollow piston type hydraulic cylinders. The device includes a pair of sleevelike members adapted to alternately engage abutments disposed adjacent opposite ends of a piston-enclosing cylinder casing, a compression spring disposed intermediate the members in a direction axially of the piston and means to slidably mount the members on an end of the piston received with the cylinder casing. The member mounting means permits movement of an engaged member relative to the piston, while maintaining the other nonengaged member stationary with respect thereto, so as to effect compression of the spring and resultant resilient cushioning of the piston.

DRAWINGS FIG. 1 is a perspective view illustrating the positioning of clustered cylinder lifts in association with an elevator car to be lifted thereby;

FIG. 2 is a vertical, sectional view taken through a clustered cylinder lift and showing the individual cylinders retracted so as to position an elevator car adjacent a lower fioor level to be serviced thereby;

FIG. 3 is a fragmentary, sectional view of the right-hand small diameter cylinder of FIG. 2, but illustrating operation of its spring cushioning device when such cylinder is moved into its extended position;

FIG. 4 is a similar to FIG. 3, but illustrates operation of the spring device when the cylinder is moved into its retracted position; and

FIGS. 5a-5d are diagrammatic views of a clustered cylinder lift showing relative positioning of the individual cylinders during various portions of elevator car travel.

DETAILED DESCRIPTION In FIG. 1, there is shown a conventional elevator lift arrangement, wherein an elevator car is adapted to be elevated within a well 11 between a lower floor level 12 and one or more upper flow levels, not shown, by operation of a pair of clustered cylinder lifts l4, 14' arranged laterally of car 10. Conventional guide rails l5, 15', which are suitably fixed to the walls of well 11, cooperate with suitable car-mounted followers, not shown, for the purpose of guiding car 10 during vertical travel thereof.

As shown particularly in the case of lift 14 in FIGS. 1 and 2, each lift includes a large diameter cylinder 16 and a pair of identically constructed, small diameter cylinders 17, which have a total effective area corresponding substantially to the effective area of large cylinder 16. Cylinders l6, 17 include, respectively, hollow or tubular pistons 18, I9; and tubular casings 20, 21, which are fixedly interconnected as by weldments 22 or, if preferred, by bolts, not shown. As is conventional, cylinder casings 20, 2I carry adjacent their open ends suitable bearing devices 24, 25 and suitable piston-sealing packing gland devices 26, 27, respectively. It will be understood that bearing devices, 24, 25, or their ring retainers 28, 29, serve as a first abutment to limit travel of pistons l8, 19 in a cylinderextended direction, whereas the closed ends 30, 31 of casings 20, 21 serve as a second abutment to limit travel of pistons 18, 19 in a cylinder-retracted direction.

Preferably, large cylinder piston I8 is pivotally fixed adjacent its lower end by pivot pin 34 to base-mounting plate 30, whereas small cylinder pistons 19 are pivotally fixed adjacent their upper ends by supporting pivot pin 37 to car-mounting bracket 39 carried by elevator car crossheads 41. By arranging pivot pins 34 and 39 in a right-angular relationship, there is afforded a universal connection, which permits the car and lifts l4, 14 to be self-orienting when necessary to compensate for slight tilting movement of guide rails l5, l5 occasioned by settling of the building subsequent to installation of elevator car 10.

Any conventional control equipment, not shown, may be employed to simultaneously supply or exhaust suitable drive fluid, such as oil, through conduits 45 into large cylinder pistons 18 of each of lifts l4, 14', for the purpose of controlling vertical movement of car 10. As best shown in FIG. 2, conduits 47 serve to provide a connection for hydraulic fluid between cylinder 20 and cylinders 21. It will be understood that subsequent to installation of lifts 14, I4, drive fluid is ad mitted through conduits 45 in order to completely fill cylinders l6, 17; air being fully exhausted from the cylinders through subsequently closable bleed openings 48, 49.

Referring particularly to FIG. 2, it will be understood that in accordance with the present invention, the ends of pistons l8, 19, which are received within cylinder casings I6, 17, are pro vided with spring cushioning devices 50, 51, respectively. Spring devices 50, 51 are similarly constructed and include, respectively, inner sleeve members 52, 53, which are supported for axial sliding movement concentrically inwardly of pistons l8, l9, and engageable with cylinder casing end walls 30, 31; outer sleeve members 54, 55, which are supported for axial sliding movement concentrically outwardly of pistons I8, 19, and engageable with bearing devices 24, 25; and coil-type compression springs 56, 57. Preferably, outer sleeve members 54, 55, are formed of a material dissimilar to that of cylinder casings 20, 21, so as to reduce the likelihood of binding or spalling during operation.

Inner sleeve members 52, 53, are provided adjacent one end thereof with a pair of aligned axially extending guide slots 58, 59, which are adapted to slidably receive guide-constraining pins 60, 61, which are in turn fixed to and extend transversely inwardly of the ends of pistons l8, 19, respectively, It will be understood that pins 60, 61 are adapted to cooperate with slot ends 58a, 59a in order to limit or constrain movement of members 52, 53 relative to pistons 18, I9, in the direction of cylinder casing end walls 30, 31. This arrangement does, however, permit sliding movement of members 52, 53, relative to the pistons in a direction towards bearing devices 24, 25 when such members are brought into engagement with cylinder casing end walls 30, 31 upon relative movement of the pistons into their retracted positions. Adjacent the other or outwardly extending ends of members 52, 53 are provided bearing devices 62, 63, which are adapted to slidably engage cylinder casings 20, 21. Bearing devices 62, 63 are provided with lengthwise extending slots 64, 65, whereas inner members 52, 53 and pistons I8, 19 are provided with radially opening apertures 66, 67 and 68, 69, respectively, in order to facilitate the flow of hydraulic fluid through and around spring devices 50, 51.

Outer sleeve members 54, 55 are provided adjacent one end thereof with radially inwardly extending annular flange portions 72, 73, which define radially inwardly extending stop surfaces 74, 75. Stop surfaces 74, 75 are adapted to cooperate with the radially extending annular end surfaces 76, 77 of pistons l8, 19 to limit or constrain movement of members 54, 55 relative to the pistons in a direction axially towards bearing devices 24, 25, while permitting sliding movement thereof, when engaged with such bearing devices, relative to the pistons in a direction axially towards cylinder end walls 30, 31.

Preferably, sleeve members 52, 54 and 53, 55 are slidably mounted directed by pistons 18 and I9, and radially spaced one from another in order to reduce frictional effects there between. However, it will be understood that a possible modification of this arrangement would be to slidably support either the inner or outer of the sleeve members on the pistons and slidably mount the other of such sleeve members thereon.

Springs 56, 57 are arranged concentrically outwardly of inner sleeve members 52, 53 and disposed intermediate bearing devices 62, 63 and outer member flange portions 72, 73 respectively. It will be understood that during movement of pistons 18 and 19 between their extended and retracted positions, springs 56, 57 are normally in a slightly compressed condition, such that they are operable to bias sleeve members 52, 54 and 53, 55 axially apart into their rest positions illustrated in FIG. 2.

Again referring to FIG. 2 it will be seen that spring device 50 is supported on piston 18 by engagement of outer sleeve stop surface 74 with piston end surface 76; spring 56 normally serving to bias inner sleeve 52 into its rest position determined by abutting engagement of slot end 58a with pin 60. Spring devices 51 on the other hand are supported on pistons 19 by engagement of pins 61 with slot ends 59a; springs 57 normally serving to bias outer sleeves 55 into their rest positions determined by abutting engagement of outer sleeve stop surfaces 75 with piston end surfaces 77.

FIGS. 5-5d illustrate relative positioning of cylinders l6, 17 during various positions of elevator car travel. In FIG. 5 cylinders 16, 17 are fully retracted so as to position elevator car at its lower floor level. Preferably, in this position, inner sleeves 52, 53 disposed in engagement with cylinder casing end walls 30, 31 and springs 56, 57 slightly compressed, such that pins 60, 61 are slightly spaced from slot ends 58a, 59a.

When it is desired to elevate the elevator car, drive fluid is introduced through conduit 45 into piston 18 and hence into pistons 19 via apertures 66 and 68, conduits 47, aperture 67 and bearing device slots 65. Although cylinders 17 have a total effective area equal to that of cylinders 16, the former tend to be extended first, as indicated in FIG. 5b, since cylinder 16 carried the weight of cylinders 17 in addition to that of car 10. Upon movement of cylinders 17 into their fully extended positions spring devices 5] become effective to prevent jolting engagement of pistons 19 with cylinder casing bearing devices 25. The operation of spring devices 51 during such movement will become apparent from viewing FIG. 3, wherein outer sleeve 55 is shown as having been brought into engagement with bearing device 25, such that relative movement between sleeve 55 and piston 19, and the resultant compression of spring 57, is initiated. Upon compression of spring 57, movement of piston 19 is smoothly arrested and the resultant increase in back pressure within cylinders 17 causes the drive fluid to become effective in extending cylinder 16 into its fully extended position indicated in FIG. 50. With cylinders 16, 17 fully extended, car 10 is disposed at the uppermost floor level to be serviced.

When cylinder 16 is moved into its fully extended position, spring device 50 serves to cushion piston 18 with respect to bearing device 24 in the same manner described above with reference to spring devices 51.

It will be understood that when it is desired to lower elevator car 10, as by withdrawing drive fluid through conduit 45 to return the lifts to either of their conditions indicated in FIGS. 5d and 5, the return compression forces stored in springs 56, 57 are effective to initiate retracting movements of the cylinders.

Operation of spring devices 51, upon return of pistons 19 to their retracted positions, is best illustrated in FIG. 4, wherein inner sleeve 53 is shown as having been brought into engagement with cylinder casing end 31. Such engagement effects relative movement between sleeve 53 and piston 19 with the result that spring 57 is compressed. Preferably, slot 59 is of a length sufficient to prevent engagement of pin 61 with slot end 5%, and resultantjolting of piston 19, when spring 57 is in its fully compressed condition.

The operation of spring devices 51 when cylinder 16 is moved into fully retracted position is similar to that described for spring devices 51 with reference to FIG. 4.

From the foregoing it will be appreciated that I have been devised a novel spring cushion device for clustered cylinder lifts, which employsa pair of sleeve members which are alternatively engageable with abutments defining relatively extended and retracted positions of a piston; a sleeve when engaged being movable relative to the piston and the nonengaged sleeve for the purpose of compressing a single piston movement cushioning spring.

Whereas only the preferred embodiment of the present invention has been described in detail herein, it will be understood that various changes may be made therein without departing from the spirit of the invention.

lclaim:

l. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said piston being hollow at least adjacent said end portion thereof, said spring device including in combination:

first and second members;

means to mount said first and second members on said piston end portion respectively radially outwardly and inwardly thereof for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said mounting means including means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second member relative to said piston in a direction axially towards said second abutment while permitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment; and single spring means disposed intermediate said members, said spring means being resiliently compressed upon sliding movement of either of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions.

2. A spring cushioning device according to claim I, wherein one of said constraining means includes pin means carried by said piston end and slot means provided in one of said members, said slot means extending lengthwise of said one member in a direction axially of said piston and slidably receiving said pin means.

3. A spring cushioning device according to claim I, wherein one of said constraining means includes radially extending stop surfaces defined by one of said members and said piston end.

4. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston being of generally tubular configuration and having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said spring device including in combination:

first and second members;

means to mount said members on said piston end portion for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said. mounting means including means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second'member relative to said piston in a direction axially towards said second abutment while pennitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment, said second member being of sleevelike configuration and supported for axial sliding movement concentrically inwardly of said piston, said first member being of sleevelike configuration and supported for axial sliding movement concentrically outwardly of said piston, said second member constraining means including pin means fixed to said piston end portion and pin means receiving slot means provided in and extending in a direction axially of said second member, and said first member constraining means including cooperating radially extending stop surfaces defined by said first member and said piston end portion; and spring means disposed intermediate said members, said spring means being resiliently compressed upon sliding movement of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions.

5. A spring cushioning device according to claim 4, wherein said second member carries a bearing device on an end thereof projecting axially outwardly of said piston end, said bearing device being arranged in sliding engagement with said cylinder casing, and said spring means is in the form of a coil spring disposed concentrically outwardly of said second member intermediate said bearing device and said first member.

6. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston being of generally tubular configuration and having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said spring device including in combination:

first and second members;

means to mount said members on said piston end portion for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said mounting means including means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second member relative to said piston in a direction axially towards said second abutment while permitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment, said second member being of sleevelike configuration and supported by said piston for axial slide movement concentrically therewithin, said second member constraining means including a pin fixed to and extending transversely inwardly of said piston end portion and a pair of aligned slots extending axially of said second member and being disposed adjacent an end thereof arranged within said piston end portion, said slots slidably receiving said pin and cooperating therewith to constrain movement of said second member as aforesaid, another end of said second member projecting axially outwardly of said piston end portion and having mounted thereon a bearing device disposed in sliding engagement with said cylinder casing, said first member being of sleevelike configuration and supported by said piston for axial sliding movement concentrically outwardly thereof, said first member having a radially inwardly extending flange portion, said first member constraining means including cooperating stop surfaces defined by said flange portion and said piston end; and

a coil-type compression spring disposed concentrically outwardly of said second member intermediate said bearing device and said flange portion in a direction axially of said piston, said spring being resiliently compressed upon sliding movement of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions, 

1. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said piston being hollow at least adjacent said end portion thereof, said spring device including in combination: first and second members; means to mount said first and second members on said piston end portion respectively radially outwardly and inwardly thereof for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said mounting means including means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second member relative to said piston in a direction axially towards said second abutment while permitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment; and single spring means disposed intermediate said members, said spring means being resiliently compressed upon sliding movement of either of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions.
 2. A spring cushioning device according to claim 1, wherein one of said constraining means includes pin means carried by said piston end and slot meAns provided in one of said members, said slot means extending lengthwise of said one member in a direction axially of said piston and slidably receiving said pin means.
 3. A spring cushioning device according to claim 1, wherein one of said constraining means includes radially extending stop surfaces defined by one of said members and said piston end.
 4. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston being of generally tubular configuration and having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said spring device including in combination: first and second members; means to mount said members on said piston end portion for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said mounting means including means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second member relative to said piston in a direction axially towards said second abutment while permitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment, said second member being of sleevelike configuration and supported for axial sliding movement concentrically inwardly of said piston, said first member being of sleevelike configuration and supported for axial sliding movement concentrically outwardly of said piston, said second member constraining means including pin means fixed to said piston end portion and pin means receiving slot means provided in and extending in a direction axially of said second member, and said first member constraining means including cooperating radially extending stop surfaces defined by said first member and said piston end portion; and spring means disposed intermediate said members, said spring means being resiliently compressed upon sliding movement of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions.
 5. A spring cushioning device according to claim 4, wherein said second member carries a bearing device on an end thereof projecting axially outwardly of said piston end, said bearing device being arranged in sliding engagement with said cylinder casing, and said spring means is in the form of a coil spring disposed concentrically outwardly of said second member intermediate said bearing device and said first member.
 6. A spring cushioning device for use in a hydraulically operated cylinder of the type employed in clustered cylinder elevator car lifts, said hydraulic cylinder having a piston and a cylinder casing defining first and second piston travel limiting abutments adjacent opposite ends thereof, said piston being of generally tubular configuration and having an end portion relatively movable axially within said cylinder casing alternately into proximity with said first and second abutments when said piston is moved respectively between extended and retracted positions thereof, said spring device including in combination: first and second members; means to mount said members on said piston end portion for movement therewith alternately into respective engagement with said first and second abutments when said piston is moved between said positions, said mounting means inCluding means to constrain movement of said first member relative to said piston in a direction axially towards said first abutment while permitting sliding movement of said first member when engaged with said first abutment relative to said piston in a direction axially towards said second abutment and means to constrain movement of said second member relative to said piston in a direction axially towards said second abutment while permitting sliding movement of said second member when engaged with said second abutment relative to said piston in a direction axially towards said first abutment, said second member being of sleevelike configuration and supported by said piston for axial slide movement concentrically therewithin, said second member constraining means including a pin fixed to and extending transversely inwardly of said piston end portion and a pair of aligned slots extending axially of said second member and being disposed adjacent an end thereof arranged within said piston end portion, said slots slidably receiving said pin and cooperating therewith to constrain movement of said second member as aforesaid, another end of said second member projecting axially outwardly of said piston end portion and having mounted thereon a bearing device disposed in sliding engagement with said cylinder casing, said first member being of sleevelike configuration and supported by said piston for axial sliding movement concentrically outwardly thereof, said first member having a radially inwardly extending flange portion, said first member constraining means including cooperating stop surfaces defined by said flange portion and said piston end; and a coil-type compression spring disposed concentrically outwardly of said second member intermediate said bearing device and said flange portion in a direction axially of said piston, said spring being resiliently compressed upon sliding movement of said members relative to said piston as aforesaid to effect cushioning of said piston end portion when moved into said positions. 